Print hammer interposer means for high speed printers



March 3, 1970 w, KAESER ET AL 3,498,216"

PRINT HAMMER INTERPOSER MEANS FOR HIGH SPEED PRINTERS Filed Dec. 9, 1968 mxwa ATTORNEY United States Patent US. Cl. 101-93 3 Claims ABSTRACT OF THE DISCLOSURE A printing mechanism having a continuously moving type carrier which is opposed by a plurality of printing hammers. A plurality of intermediate members are actuated by the printing hammers to effect a printing of a selected type. The printing hammers and members are assembled in groups, such that the number of hammers and members comprising a group cause the corresponding number of characters to be printed during each complete passage of the type carrier.

Cross reference to related applications This invention is a continuation-in-part of an application by Wolfgang Kaiser and Bernhard Cramer, Ser. No. 603,297, filed Dec. 20, 1966 (abandoned).

Printing mechanism for a page printer The present invention relates to a printing mechanism for a page printer intended for the use in data processing in which a continuously movable type carrier is opposed by a plurality of printing hammers stationarily arranged in the line direction, and by which the recording medium, during the printing, strikes a predetermined type of the type carrier.

In order to increase the operating speed of printing mechanisms intended for the use in data processing systems, it has been suggested that the characters of a text not be printed successively, but within a certain line of the text, the characters to be printed simultaneously or almost simultaneously. The most well known arrangement of this kind is the so-called line printer (line-at-a-time printer). Of course, a high cost is involved to the simultaneous printing of several characters, because the number of separately selectable printing elements (e.g. printing hammers) must be just as large as the number of characters to be printed and, because there must be effected an electronic storing of these characters.

Such a high cost does not appear to be justified in all cases, because oftentimes there are only required small increases in speeds or velocities which are not achievable with the aid of conventional types of printers, such as teleprinters, but which are still far below the limit of performance of the aforementioned line printers.

One arrangement considering these points of view proposes to employ only the number of printing hammers as is necessary for achieving the desired speed. The printing hammers are arranged in equally spaced relation along the line to strike the paper against a type roller (platen) which is continuously rotating behind the paper. All of the hammers are moved forward in common along the line. After this line has been typed, the heads must be moved back in common in direction towards the begin ning of the line, as corresponds to their mutual spacing or space relationship. At the same time there is effected the paper feed.

A printing mechanism of this type is unsuitable for the I use in equipment which, for effecting a manual operation, is provided with a transmitting keyboard; and for the purpose of supervising the transmitted text, performs the printing as well, therefore irrespectively of the required parallel input, the text is printed at several parts of the line simultaneously, and is only gradually completed. This is a hindrance with respect to the checking by the operator, since the time required for printing a partially filled line is the same as that required for the printing of a complete line.

In distinction thereto, another arrangement is known in which two electromagnetically actuated printing hammers are arranged next to one another on an advancing carriage to strike the paper to be printed against a permanently rotating type roller (platen) which is positioned behind the paper. During each rotation of the platen two adjacent characters are printed.

The movement by the action of the advancing or feed device is made in a double step. The use of more than two adjacent hammers for increasing the speed is obvious. A disadvantage of this arrangement is the fact that the printing hammers, upon reaching the end of the line, must be rapidly returned to the beginning of the next line; this causes difficulties due to the rather large inertial mass which must be moved.

All of the aforementioned disadvantages are avoided by the printing mechanism proposed in accordance with the present invention. This inventive type of printing mechanism is characterized by the fact that a carriage device capable of being moved in a step-by-step manner along the line, is provided with n intermediate members projecting into the space between the record medium and the printing hammers, that the printing hammers are subdivided into n groups subject to the same selection, and that a printing is only effected via the intermediate members.

By this arrangement, it is possible to design the carriage device for effecting more than two parallel printing operations without the size of mass being moved having any appreciable effect upon the reset time (return time) of the carriage device.

The invention will now be explained in detail with reference to an embodiment shown in the accompanying drawing.

In the shown example a continuously rotating type roller of the known kind which is used as the type carrier 4 and which, with each rotation, leads its entire stock of types past each line printing position to make them available to electronically controlled selection means in the case of on-the-fly printing. It is also conceivable, however, to design the type carrier 4 as a horizontally rotating type tape or belt, or in the shape of type rods arranged next to one another.

In front of this type carrier 4, which is designed as a type-carrying platen and is continuously driven by a motor 7, there is positioned the recording medium 6 which, in a known manner, is guided within the range of the printing zone, closely in front of the rotating platen 4. In front of the recording medium 6, and in the longitudinal direction of the platen, the ink ribbon 5 is held in position in a conventional manner. At a certain dis- 'tance in front of the ink ribbon 5 there are arranged several printing bails 1a to 1d which, on either side, are rotatably arranged on a longitudinal axis 11 which, in turn, is supported in stationary bearing brackets 1111. On their longitudinal edges facing the platen 4, the printing bails 1a to 1d are provided, at certain relations, with printing hammers 1 which are staggered in relation to one another. The vertical bail ends are extended on the one side in excess of their centers of rotation, and are designed to be controlled -by actuating means 12 and which, via separate lines 13, are capable of being individually energized by an electronic control unit 14 including a comparator, the bails 1a to 1d are caused to perform a limited swivel movement extending in the direction indicated by the arrow A. Into the space between the ink ribbon and the printing hammers 1 there project a number of intermediate members 2 which, at least in their lower part, have the properties of flat springs. These intermediate members 2 are mounted on a carriage device 3 which, via a switching shaft 9a, designed as a spindle, is moved in a step-by-step manner in the direction of printing. The carriage device 3, for the purpose of elfecting a sideway guidance, is provided with a projecting portion 3a which is in engagement with the guide slot provided in a guide plate 10. The respective step-by-step switching of the shaft 9a in time and amount, is controlled by a feed control unit 9 which is arranged at one end of the shaft 9a. The other end of this shaft is supported in a stationary bearing which, however, is not shown in the drawing for the sake of clarity. The feed control unit 9 is, via a belt drive 8, in mechanical connection with the motor 7 and, via a line 15, capable of being controlled by the control unit 14 for effecting the step-by-step switching. In order that the carriage device 3, after completing its advancement in the printing direction, can be rapidly returned to its beginning-of-line position, it can be permanently connected to a carriage return spring which is tensioned in the course of the advancement of the carriage in the printing direction. With the aid of disengaging means, and at the end of the line, the engagement between the switching shaft 9a and the carriage device is eliminated, so that the latter, under the action of the spring, is capable of jumping back into its normal position.

The intermediate members 2-in the present case four-are spaced corresponding to the lateral divisional spacing of the types 4a, and the printing hammers 1 of the individual printing bail 1a to 1d arealso arranged in a spaced relation corresponding to the four-fold grouping of the members 2. The bails la to 1d are staggered with respect to one another by one divisional spacing, so that under the condition of a respectively four-fold step switching of the carriage device 3, one printing hammer of a certain printing bail 1a to 1d is at each printing time position placed opposite each intermediate member 2.

According to the invention, the swivel movement of the bails 1a to 1d is controlled by the actuating means 12, such that the printing of a character is only effected at the point where a hammer 1 meets one of the intermediate members 2 which is then thrown forward and, via the ink ribbon 5, hits the recording medium 6 against the selected type 4a which is in the printing position.

By providing a plurality of intermediate members 2 the printing of a corresponding plurality of types is ac-- complished within one rotation of the type carriers 4 during the stepwise printing of each line. Since the intermediate members 2, as passive elements, have no massive selection means, they can be designed to' be of very light Weight. Then entire carriage device 3 can be designed in such a way that the mass inertia forces which hitherto appeared during the forward stepping and return of such carriage devices, no longer represents an insurmountable limiting restricting effect.

Since the printing bails 1a to 1d have a greater inert mass than an individually controllable printingv hammer, it is conceivable, by employing the idea of the present invention, to provide a line printer having a plurality of separately controllable or selectable printing hammers which are capable of being operated or energized in a groupwise fashion.

We claim:

1. A printing mechanism having a continuously moving type carrier, a plurality of printing hammers arranged opposite said type carrier along a printing line, and a recording medium intermediately arranged between said hammers and type carrier, such that during printing, said record medium is momentarily hit against a preselected type of said carrier, the improvement comprising:

a carriage device mounted on a shaft and movable in a step-by-step manner along a printing line;

means coupled to said shaft for providing the step-bystep motion of said carriage;

n intermediate members attached to said carriage device and projecting into the space between said record medium and hammers;

said hammers being subdivided into a plurality of groups, each group including n printing hammers, and the step-by-step movement of the carriage corresponds to the n grouping of the printing hammers;

n parallel and pivotally mounted bails extending in parallel to the type carrier, and each of said 11 printing hammers is mounted on one of said bails in a staggered manner one above the other, whereby the pivotal movement of said bails effects the displacement of said hammers; and

control means for selectively effecting the displacement of said hammers toward said type carrier, where-by by means of said It intermediate members said record medium is caused to hit against the selected type of said carrier.

2. A printing mechanism according to claim 1, wherein said type carrier is a continuously rotating type roller, and wherein, after each complete rotation of said roller, said carriage device is caused to advance by an n-step corresponding to the number of n intermediate members.

3. A printing mechanism according to claim 2 wherein the divisional spacing of said intermediate members and prnting hammers corresponds to the lateral type spacing of the type on the type carrier.

References Cited UNITED STATES PATENTS 2,766,686 10/1956 Fomenko et al. 101-93 2,813,481 11/1957 Hansen 101-93 2,893,313 7/1959 Pekar et al 101-93 3,018,721 1/1962 Monticello et al. a 101-93 3,157,115 11/1964 West et al. 197-49 X 3,332,343 7/1967 Sims 101-93 0 WILLIAM B. PENN, Primary Examiner 

